tert-Butyl 3-(2-ethoxy-2-oxoethyl)pyrrolidine-1-carboxylate → tert-Butyl 3-(2-oxoethyl)pyrrolidine-1-carboxylate

Temperature

-78 °C

A flask was charged with tert-butyl 3-(2-ethoxy-2-oxoethyl)pyrrolidine-1-carboxylate (160 g, 623 mmol) and dichloromethane (2,500 ml) and cooled to −78° C. A solution of diisobutylaluminum hydride (800 ml, 1.10 equiv) was added dropwise, such that the internal temperature was maintained at −78° C. After 1 h at 78° C., the reaction mixture was quenched by the addition of 30 ml of methanol. After warming to ambient temperature, the mixture was filtered and the filter cake was washed with dichloromethane (3×1,000 mL). The filtrate was dried over sodium sulfate, filtered and concentrated. The residue was purified by column chromatography on silica gel (ethyl acetate/petroleum ether gradient) to afford tert-butyl 3-(2-oxoethyl)pyrrolidine-1-carboxylate as light yellow oil.

1. temperaturewas maintained at −78° C
2. customthe reaction mixture was quenched by the addition of 30 ml of methanol
3. temperatureAfter warming to ambient temperature
4. filtrationthe mixture was filtered
5. washthe filter cake was washed with dichloromethane (3×1,000 mL)
6. dry with materialThe filtrate was dried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated
9. customThe residue was purified by column chromatography on silica gel (ethyl acetate/petroleum ether gradient)

ORD record

ord-498ce4852184431cbe890fbfc3a4bd8d

Source dataset

uspto-grants-2013_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08455477B2